The invention relates to couplings in general, and more particularly to improvements in couplings for hoses and similar conduits. Still more particularly, the invention relates to improvements in couplings which can be used to sealingly connect the end portion of a hose to a nipple, e.g., to a nipple under the hood of a motor vehicle.
It is known to provide the coupling between a hose and a nipple with an annular sealing device which is forced into the nipple to prevent uncontrolled escape of the conveyed gaseous or hydraulic fluid. It is also known to connect the end portion of the hose with a tubular connector which is surrounded by the sealing device and can be separably coupled to the nipple by one or more resilient hooks which are integral with a ring. The latter is placed around and is maintained in frictional engagement with the external surface of the tubular connector. The end portion of the hose is slipped onto the rear portion of the connector behind the ring, and the front portion of the connector has circumferential grooves for O-rings which constitute the sealing device and are forced into the nipple before the hooks engage a flank at the exterior of the nipple. The outer diameter of the front portion of the connector matches or approximates the inner diameter of the nipple. The external surface of the nipple is further provided with substantially wedge-like cams which can disengage the hooks from the flank in response to rotation of the nipple and the end portion of the hose relative to each other so that the connector can be withdrawn from the nipple.
A drawback of the just described conventional coupling is its complexity, length, bulk and high cost. Moreover, the insertion of O-rings into the nipple necessitates the exertion of a substantial force. Still further, and since the end portion of the hose is merely slipped onto the rear portion of the connector, the seal between the hose and the connector is likely to be interrupted in response to increasing pressure in the interior of the hose and/or nipple; in fact, the hose is likely to become completely separated from the connector. Such separation can also take place in response to the application of a pronounced pull in a direction to move the end portion of the hose away from the nipple which receives the front portion of the connector. The frictional engagement between the ring, which carries the hooks, and the connector is often insufficient to prevent separation of the ring and connector from each other when the connector is pulled in a direction away from the nipple and/or vice versa.